Modifies the informational record of an indexed mail file,
    including the mail file name, the default mail file name, and
    the wastebasket name.

    Format

      MAIL$MAILFILE_MODIFY  context ,in_item_list ,out_item_list

1  –  Returns

    OpenVMS usage:cond_value
    type:         longword (unsigned)
    access:       write only
    mechanism:    by value

    Longword condition value. All utility routines return a condition
    value in R0. Condition values that can be returned by this
    routine are listed under Condition Values Returned.

2  –  Arguments

 context

    OpenVMS usage:context
    type:         longword (unsigned)
    access:       modify
    mechanism:    by reference
    Mail file context information to be passed to mail file routines.
    The context argument is the address of a longword that contains
    mail file context information returned by MAIL$MAILFILE_BEGIN.

 in_item_list

    OpenVMS usage:itmlst_3
    type:         longword (unsigned)
    access:       read only
    mechanism:    by reference
    Item list specifying options for the routine. The in_item_list
    argument is the address of a list of item descriptors, each of
    which specifies an option and provides the information needed to
    perform the operation.

    The item list is terminated by longword value of 0.

3  –  Input Item Codes

 MAIL$_MAILFILE_DEFAULT_NAME

    MAIL$_MAILFILE_DEFAULT_NAME specifies the default file
    specification that the Mail utility should use when opening
    a mail file. The buffer address field points to a buffer that
    contains a character string of 0 to 255 characters that defines
    the default mail file specification.

    Specify a value from 0 to 255 in the buffer length field of the
    item descriptor.

    If you specify the value 0 in the buffer length field of the
    item descriptor, MAIL$MAILFILE_MODIFY uses the current default
    directory as the default mail file specification.

    If you do not specify MAIL$_MAILFILE_DEFAULT_NAME, MAIL$MAILFILE_
    MODIFY creates the default mail file specification from the
    following sources:

    o  Disk and directory defined in the caller's user authorization
       file (UAF)

    o  Subdirectory defined in the Mail user profile

    o  Default file type of .MAI

 MAIL$_MAILFILE_NAME

    MAIL$_MAILFILE_NAME specifies the name of the mail file that the
    Mail utility should open. The buffer address field points to a
    buffer that contains a character string of 0 to 255 characters.

    Specify a value from 0 to 255 in the buffer length field of the
    item descriptor.

    If you do not specify MAIL$_MAILFILE_NAME, the default mail file
    name is MAIL.

 MAIL$_MAILFILE_WASTEBASKET_NAME

    MAILFILE_WASTEBASKET_NAME specifies a new folder name for the
    wastebasket in the specified mail file. The buffer address field
    points to a buffer that contains a character string of 1 to 39
    characters.

 out_item_list

    OpenVMS usage:itmlst_3
    type:         longword
    access:       write only
    mechanism:    by reference
    Item list specifying the information you want the routine to
    return. The out_item_list argument is the address of a list of
    item descriptors, each of which describes an item of information.
    The list of item descriptors is terminated by longword value of
    0.

4  –  Output Item Code

 MAIL$_MAILFILE_RESULTSPEC

    When you specify MAIL$_MAILFILE_RESULTSPEC, the Mail utility
    returns the resultant mail file specification. The buffer address
    field points to a buffer that receives a character string from 0
    to 255 characters long.

    Specify a value from 0 to 255 in the buffer length field of the
    item descriptor.

5  –  Description

    If a mail file is not specified, the currently open mail file is
    used.

6  –  Condition Values Returned

    MAIL$_ILLFOLNAM    The specified folder name is illegal.
    MAIL$_INVITMCOD    The specified item code is invalid.
    MAIL$_INVITMLEN    The specified item length is invalid.
    MAIL$_MISREQITEM   The required item is missing.
    MAIL$_NOTISAM      The message file is not an indexed file.
    MAIL$_OPENIN       Mail cannot open the file as input.
    SS$_ACCVIO         Access violation.
    Any condition value returned by $CLOSE, $FIND, $PUT, and $UPDATE.